Thursday, May 29, 2014

Kalydeco, VX-809, & VX-661

In January 2012, the CF community was buzzing over the FDA’s expedited approval of the drug that has brought us as close to a cure as we have been: Kalydeco. For the 4% of the CF population that carries a copy of the G551D mutation, the drug has been a major game changer. While it’s not the cure that we are still waiting for, the promise that it is showing in the improvement in the quality of life in patients who have been on it is remarkable!

Kalydeco, or Ivacaftor if you use the generic name, is developed by Vertex Pharmaceuticals with significant funding/help from the Cystic Fibrosis Foundation, and they are currently working through various phases of the study process for a combination of Kalydeco and VX-809 or Kalydeco and VX-661. The drug(s) help to restore CFTR function to the surface of the cell, which means that the flow of salt and other fluids to the lungs is restored, and mucus in the lungs can be thinned (cff.org). The reason that this is so revolutionary for the disease is because up until this point, treatments only targeted and treated the symptoms. Kalydeco is the first drug to actually target and treat the underlying cause of CF.

Currently, Kalydeco is approved for patients with a copy of G551D who are age 6 and older. Studies are underway for patients with a copy of G551D who are ages 2-6, and it is hoped that approval for that age group will happen soon.

VX-809 and VX-661 are not approved by the FDA yet, as they are still going through various phases of the study process. Phase 3 studies are currently underway for the Kalydeco/VX-809 combination for patients who are homozygous F508del (or those who have 2 copies of that mutation), and Phase 2 studies are underway for heterozygous F508del patients (or those that have 1 copy of that mutation and 1 copy of another mutation). It is expected that approval for the homozygous F508del patients will happen in the next few years, and there is hope that the heterozygous F508del population will not take too much longer to get approval. Last time I checked on VX-661, I think I remember reading that it was heading to Phase 2 trials, and was showing more promise than VX-809. It would target the same populations as VX-809.

The reason VX-809/VX-661 has so many people on edge waiting for the studies to finish and approval to happen is because these drugs target a huge portion of the CF population; approximately 90% or more of the CF population carries at least 1 copy of F508del. Once VX-809/VX-661 are approved for both the homozygous and heterozygous population, a vast majority of CF patients will hopefully see a dramatic improvement, and have a chance at living a longer, healthier life than they would have without these drugs.

In the first paragraph, I mentioned that the CFF provided a lot of support in various ways through funding, which includes a $75 million investment for Kalydeco alone (cff.org). This is why so many of us reach out and ask for donations and support for the Great Strides walks! Because CF is an orphan disease, government funding is practically, if not totally, nonexistent. Our fundraising efforts as families, friends, and others who care about the disease, is what is funding these studies for our loved ones. It’s why we’re moving closer to a cure! $.90 of every $1 raised goes back to the CFF, which in turn goes into the research for treatments like Kalydeco.

The drug doesn’t come without a hefty price tag: 1 year of Kalydeco can cost approximately $300,000. I’m hearing reports from other CF parents in the US that they are not having to pay a lot out of pocket for the drug and their copays aren’t too bad, but the extremely high costs is a reason why other countries around the world have not yet approved Kalydeco for their patients. In Australia, for example, they are still fighting the government to approve Kalydeco for patients with a copy of G551D. My fear is that once VX-809/VX-661 gain FDA approval, patients in countries that are struggling to get Kalydeco are going to be going through additional battles to get the new combination drugs approved, even though a huge portion of the CF population would benefit.